440 balancer

can anyone identify this harmonic balancer? it's on a 69 HP 440 casting date 2-21-69 but i was wondering if it was a cast crank balancer because of the drillings in it? i guess it's also possible that it's may be a 6 pack balancer.

the motor has been fitted with a later timing cover and i thought possibly someone changed it so the timing marks would line up

any ideas?

P1010046.JPG